The present invention relates to a system and a method of power plant component optimization, and more particularly to optimization of a heat recovery steam generation (HRSG).
Current control systems attempt to load (or unload) turbines, HRSGs, and various other components of a power plant using desired loading rates. If the loading rates for various turbines are very high, large thermal gradients may develop in the HRSG leading to high stresses and uneven thermal expansion that may result in shorter equipment life. On the other hand, slow loading rates may reduce thermal gradients and lengthen equipment life, but the slow loading rates may increase fuel costs and reduce plant availability. Accordingly, the current controls may categorize the start-ups as hot, warm or cold. Each of these start-up states uses loading rates slow enough to protect the components of the HRSG for any startup in the same category, but may be sub-optimal for many uses. Consequently, such controlling methods may result in sub-optimal performance and higher operating costs. Therefore there is a need for an improved system and method for optimizing usage of the HRSG.